This invention relates to an electronic device forming a bidirectional interface for controlling a load switching power element, the load being for example a filament lamp, a solenoid valve, or a motor.
Such electronic devices are known which are mounted in particular on automotive vehicles and which are connected to inputs/outputs of a central unit formed for example of a microprocessor to control the power element and to indicate and diagnose faulty operations of the outer elements each formed of the load.
However, these known devices necessitate a connection with the central treatment unit to transport the power element control signal and another different connection to transmit to the central unit the information signal relative to a faulty operation in particular of the load. In the case where several power elements are to be controlled, it is necessary to use a great corresponding number of inputs/outputs of the microprocessor and thus to increase the size of same. It is possible to reduce the number of connections related to the transmission of the faulty operation information signals by grouping these signals. However, as a result of this grouping, the defective elements cannot be distinguished from one another unless an additional bidirectional circuit is used.
The design of the known systems makes it therefore necessary to use either a greater number of inputs/outputs of the microprocessor, or an additional integrated circuit, resulting in a substantial cost increase.